What happened
During a scheduled international flight, an aircraft was performing its final approach to land on runway 10. As the aircraft reached approximately 20 metres of altitude and 50 metres from the runway threshold, the pilot instructed the co-pilot to reduce power to idle. At this precise moment, the propeller reversing mechanism engaged on both engines.
The sudden activation caused the aircraft to nose down and tilt toward the left. Despite the crew applying right rudder and attempting to correct the attitude with increased power, the aircraft failed to respond and struck the runway surface. The impact caused a series of bounces that resulted in the left wing and the left engine being torn from the airframe. The aircraft then veered off the runway, traveling approximately 250 metres from the end of the runway before coming to rest upside down in a grassy area. All 24 occupants sustained injuries, and the aircraft was destroyed.
Findings
Investigations revealed that the electro-mechanical reverse safety device, which is intended to prevent the throttles from being moved into reverse position until the landing gear struts are compressed by the aircraft's weight, was inoperative. This mechanical deficiency allowed the propeller reversing system to be activated while the aircraft was still airborne.
The premature activation of the propeller reversing system caused a sudden loss of lift, leading to the uncontrolled descent and subsequent crash. While official findings focused on the failure of the safety mechanism and improper pilot technique, an unofficial report suggested that liquid from a paper cup on the center console may have spilled onto the gear levers, potentially causing an electrical short-circuit that triggered the reversers.